Whatever the type of self winding seat belt, the inertia reel, i.e. the automatic belt winder, elastically returns the belt, once attached, to keep it tensioned against the chest of the passenger and the belt is therefore automatically adapted to the passenger's morphology. In normal vehicle utilization conditions, the belt can be freely unwound opposing the elastic returns means of the inertia reel. However, when a shock to the vehicle tends to throw the passenger forward, for example during an accident, a high deceleration, or in a curve taken at high speed, the inertia reel blocks the movement of the belt by means of a locking mechanism integrated into the inertia reel, of the type known by a person skilled in the art, to securely hold the user against the seat.
To ensure correct operation of the locking mechanism, the orientation of the mechanism in relation to the vertical or the horizontal must be relatively accurate otherwise there is a risk that the belt will not lock or, inversely, the inertia reel may remained locked even under normal vehicle utilization conditions.
In vehicles where the inertia reel is attached to the chassis or the structure of the vehicle, the position of the inertia reel is defined by the attitude of the vehicle and is therefore independent of the seat adjustment position.
In vehicles including seats with an integrated belt, it is known to place the inertia reel in the backrest of the seat. As the backrest of the seat can be inclined, the inertia reel is equipped with means for automatically correcting the relative orientation of the locking mechanism in relation to the backrest, according to the inclination of the backrest, to ensure correct operation of the locking mechanism irrespective of the inclination. However, these correction means integrated into the inertia reel considerably increase cost.
Also, to improve user's comfort, the seat may include means for adjusting its height or for inclining the seat pan, as is shown, for example, in French Patent document FR A 2433433. The inclination adjustment means, also called tilt adjustment, enable the seat pan to be inclined by pivoting around a transverse horizontal axis. The height adjustment means enable the height of the seat pan to be modified in relation to the floor of the vehicle.
These height adjustment means can be made so that they induce a movement of the seat parallel to itself, for example by a deformable parallelogram system, these systems then being called parallel height adjustment systems. The vertical movement of the seat pan can also be accompanied by a variation in the inclination of the seat pan, the system then being called a non-parallel height adjustment system, the adjustment means simultaneously ensuring the height adjustment and the tilt adjustment. In both cases, the seat can also include specific tilt adjustment means independent from the height adjustment means. Such seats can include a hinged backrest adjustable in inclination in relation to the seat pan. The backrest framework can also be fixed in relation to the seat pan framework or be common with it, in which case it is the position of the whole seat assembly which is adjusted by the height adjustment and tilt adjustment means.
The aim of this invention is to propose a seat including adjustment means capable of varying the inclination of the seat pan and including a safety belt with an inertia reel integrated into the seat. Its purpose is, in particular, to propose a new system enabling correct operation of the inertia reel to be ensured, irrespective of the inclination of the seat pan, while using conventional-type inertia reels, not including integrated correction means, and therefore less costly than the latter.
With these targets in mind, the subject of the invention is a seat for automobile vehicles including a seat belt and a belt inertia reel attached to the seat and equipped with seat belt locking means, and seat pan position adjustment means enabling the seat pan to be inclined by a pivoting movement around the transverse horizontal axis characterized in that the inertia reel is attached to the seat pan and installed so as to pivot around an axis more or less parallel to the transverse horizontal axis, and the seat includes first correction means to correct the angular position of the inertia reel in relation to the seat pan, according to the inclination of the seat pan and thus conserve a more or less constant orientation of the inertia reel in relation to the vehicle. According to a first design, the first correction means include a pivoting cam acting on the casing of the inertia reel or, according to a second design, the first correction means include a sliding cam acting on the casing of the inertia reel.
It is specified that the seat pan position adjustment means signify both the specific tilt adjustment means acting only on the inclination of the seat pan and the means ensuring combined and simultaneous adjustment of the inclination and the height of the seat pan.
The correction means, for example in the form of a cam, are installed on the framework of the seat pan and are shaped to act directly on the inertia reel. The latter is installed so as to pivot around a pin also attached to the framework of the seat pan. The correction means are coupled with the position adjustment means, for example by means of a linkage or a cable, so that, maneuvering the adjustment means automatically commands the correction means, for example by activating the rotation of the cam.
According to a specific arrangement, the seat includes both specific tilt adjustment means and non-parallel height adjustment means enabling the height of the seat pan to be modified by a non-parallel movement of the seat pan in relation to the floor of the vehicle, the first correction means mate with the height adjustment means and the seat pan includes second correction means, combined with the first correction means, and shaped to mate with the tilt adjustment means, to correct the angular position of the inertia reel in relation to the seat pan according to the position of the tilt adjustment means.
In this case, the seat includes tilt adjustment means independent of the height adjustment means. The two correction means are coupled together and moreover are directly coupled, for example, by means of linkages or cables, to the associated adjustment means, so as to give the inertia reel the angular position required for any tilt adjustment or height adjustment modifying the inclination of the seat pan.
As the correction means are combined together, when the user operates either alternately or simultaneously the seat pan height and tilt adjustment means, the correction means act always in an adequate manner on the angular position of the inertia reel.
In this specific arrangement, and according to a first design, the correction means include a first pivoting cam nested within a second pivoting cam placed around the first cam, each of the cams being respectively connected to one of the adjustment means.
The first cam can be installed so as to pivot around a pin attached to the framework of the seat pan and its pivoting is, for example, controlled by the height adjustment means. The second cam includes a hole shaped to house the first cam and comes into contact with the inertia reel, and its pivoting is controlled by the tilt adjustment means. This nested arrangement of the two cams enables a variation in the distance between the pivoting axes of the cams to be obtained when the two cams rotate.
The combined arrangement of the correction means enables a correction of the angular position of the inertia reel to be ensured when an action is made on one or the other of the two seat pan adjustment means or on the two simultaneously. Also, the adjustment mechanism made thus is compact and small.
According to a second design, also for the case where the seat includes both non-parallel height adjustment means and specific tilt adjustment means, the correction means include a truncated cone-shaped cam pivoting around a rotation axis and translatable axially along the axis, the pivoting control means and the truncated cone cam translation control means being respectively connected to the tilt adjustment means and to the height adjustment means.
The cam is installed so as to pivot around a pin attached to the framework of the seat pan and can also slide along this pin. As it is substantially shaped in the form of a truncated cone, when the rotational movement of the cam is fixed but moves in translation, the inertia reel bears then on the oblique generatrix of the cam and a pivoting of the inertia reel is obtained by the variation of the distance between the axis of the cam and the contact point of the cam with the inertia reel. When cam translation movement is fixed and the cam is rotated, the radius made by an external spiral profile of the cam is varied also causing a pivoting of the inertia reel.
According to a third design, the correction means include a first deformable parallelogram attaching a support of the seat to a bellcrank installed so as to pivot around the seat pan hinge pin and a second deformable parallelogram connecting the bellcrank to the inertia reel, the support being fixed in position in relation to the vehicle and comprising a position datum in relation to which the orientation of the inertia reel remains constant irrespective of the variations in seat pan inclination.
The support is, for example, a lug attached to a movable part of a longitudinal adjustment slide of the seat, to which the seat is attached by pivoting links used to adjust the position of the seat pan, especially to adjust the height. According to a specific arrangement, the bellcrank consists of two arms which extend radially from the ends of a tube.
In this specific arrangement, the arms are connected to the support and to the inertia reel by a metallic wire, the ends of which are attached to the support and to the inertia reel respectively, and a center elastically deformable portion is held onto the ends of the arms.
The invention will be better understood and other advantages will appear in the description which will be given, as an example, of a seat pan in compliance with the invention. Refer to the appended drawings on which: